The present invention relates to a polishing composition used in precision polishing the surface of a wafer for semiconductor devices and a polishing method using the same.
A wafer cut out from an ingot is generally subjected to coarse polishing in a wrapping process, then, further subjected to precision polishing in a polishing process. Conventional polishing composition used in the polishing process is disclosed in Japanese Laid-Open Patent Publication No. 49-76470, Japanese Laid-Open Patent Publication No. 2-158684, Japanese Laid-Open Patent Publication No. 8-113772, Japanese Laid-Open Patent Publication No. 10-309660, Japanese Laid-Open Patent Publication No. 11-214338, and Japanese Laid-Open Patent Publication No. 11-116942.
During a processing of a wafer, haze occurs on the surface of the wafer in some cases. Haze not only decreases the electric property and yield of a semiconductor device but also becomes a cause for decrease in the detection limit in measuring particles adhered on the surface of the wafer. As the quality required for wafers is becoming even stricter with higher performance and higher integration and density of semiconductor devices being required, the haze levels of the surface of the wafer precision polished by the conventional polishing composition is not necessarily sufficient at present.